/*
 * Copyright (C) 2022, 2023, THL A29 Limited, a Tencent company. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation. THL A29 Limited designates
 * this particular file as subject to the "Classpath" exception as provided
 * in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License version 2 for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

package com.tencent.kona.java.nio;

import java.lang.reflect.Field;
import java.nio.Buffer;
import java.nio.ByteBuffer;

public class DirectBufferUtil {

    private static Field addressField;

    public static long address(ByteBuffer bb) {
        try {
            return getAddressField().getLong(bb);
        } catch (IllegalAccessException e) {
            throw new RuntimeException("Cannot get address", e);
        }
    }

    private static Field getAddressField() {
        if (addressField == null) {
            try {
                addressField = Buffer.class.getDeclaredField("address");
                addressField.setAccessible(true);
            } catch (NoSuchFieldException e) {
                throw new RuntimeException("Cannot get address field", e);
            }
        }

        return addressField;
    }
}
